Polycythemia VeraThrombocythemia, EssentialPolycythemiaJanus Kinase 2ThrombocytosisPrimary MyelofibrosisMyeloproliferative DisordersReceptors, ThrombopoietinPipobromanErythroid Precursor CellsThrombosisPlatelet CountHydroxyureaMegakaryocytesAloeGranulocytesErythropoietinThrombopoietinPhlebotomyMutation, MissenseCarbazilquinoneMutationErythropoiesisAmino Acid SubstitutionLeukocytosisLeukemia, Myeloid, Chronic, Atypical, BCR-ABL NegativeGPI-Linked ProteinsSplenomegalyBone MarrowReceptors, ErythropoietinIsoantigensBloodlettingHomozygoteHematocritBlood PlateletsHematopoietic Stem CellsHematopoiesis, ExtramedullaryPoint MutationErythroid CellsPlatelet Aggregation InhibitorsThrombocytopeniaReceptors, CytokineThrombopoiesisDNA Mutational AnalysisHeterozygoteErythrocyte InclusionsLeukemia, Myelogenous, Chronic, BCR-ABL PositiveInterferon-alphaColony-Forming Units AssayProto-Oncogene ProteinsHematopoiesisBudd-Chiari SyndromeAnemia, Refractory